Plugging tool



w. W. DoLLlsoN 3,036,637

PLUGGING TOOL 3 Sheets-Sheet l 2 ,cla 3 ,cva-4 May 29, 1962 Filed March 14, 1960 pm i May 29, 1962 w. W. DoLLlsoN PLUGGING TOOL 5 Sheets-Sheet 2 Filed March 14, 1960 nl a i 5 M m m a 0.4/

May 29, 1962 Filed March 14, 1960 w. w. DOLLISON PLUGGING TOOL 3 Sheets-Sheet 3 MMM atnt flfe 3,3,637 Patented May 29, i962 Delaware Filed Mar. 14, 1960, Ser. No. 14,914 8 Claims. (Cl. 166-134) This invention relates to wire line operable means for the completion of a multiple zone well, and more specitically to a latchable plugging tool for use in such completion operations whereby two zones may be separately produced and in which either Zone may be reworked by wire line while allowing the other zone to `be produced.

'Ihis application is a continuation-in-part of a divided out portion of my parent application Serial No. 729,682, filed April 21, i958, and entitled, Means for Carrying Out a Removable Flow Tube Program, now Patent No. 2,962,097.

Heretofore it has been the practice in multiple zone well completion to use two separate tubing strings in which one string extends downwardly to one production zone and the other string extends downwardly to the second production zone. The tubing strings are packed olf to the casing above and below the upper zone so as to allow simultaneous separate production of the two zones. Although this practice permits limited reworking `operations to be carried out, without pulling the tubing strings (eg, perforating of the lower Zone, and/or chemical treatment of either zone), it does not permit enough. To fully rework either Zone it is necessary to pull and later replace the tubing, which is costly and time-consuming since it requires a tubing handling rig to be kept at the well, or re-erected as needed.

The present invention has `been made to provide equipment to overcome the above limitations by permanently installing two tubing strings in a multiple zone well, as will later be described. After this installation has `been made, the rig may be disassembled and removed to another well for use there. Thereafter, all operations in the well are carried out by wire line operations which are considerably faster and more economical. The well installation can then be completed so that each zone produces separately or simultaneously through the two tubing strings. If reworking operations are later required, the well installation can be changed, without pulling the tubing, so that either zone may be fully reworked while the other zone is free to produce simultaneously while reworking operations are carried out.

One example of the necessity of a reworking operation is where water encroachment is encountered. In this case, the producing formation must be cemented, the excess cement must be removed, and the zone reperforated above the water level. In the present invention such reworking operation may be carried on in the lower zone, and repeated as necessary, while the upper zone continues in production.

Another example is where an exploratory hole is drilled and a number of producing formations is penetrated. it is only necessary to install one packer above the uppermost formation, the lower packer being installed at a desired level. rl`hen all formations except two are cemented. Thereafter, cementing and perforating operations can be carried out, as desired, without the necessity for pulling the permanently installed tubing.

The primary object of this invention is to provide wire line operable means for use in producing and reworking a multiple zone well by wire line equipment alone so that a zone or zones below the bottom packer may be produced simultaneously with and independently of the zone or zones above the packer, so that the upper zone or zones may be independently reworked simultaneously with the production of the lower zone or zones, and so that the lower zone or Zones may 'be independently reworked simultaneously with the production of the upper zone or zones.

A further object of the invention is to provide a plugging tool for use in a multiple Zone well and in which the plugging tool may be run into the well, landed and locked in place in the well and retrieved from the well by use of wire line equipment.

A yet further specific object is to provide a latchable well tool adapted to be landed by wire line in a landing nipple having spaced apart upwardly and downwardly facing shoulders, comprising a vertically disposed generally cylindrical outer mandrel, means on the upper end of said outer mandrel for engaging the upwardly facing shoulder of said landing nipple, a plurality of downwardly extending, resilient, elongated finger members secured at the upper ends thereof to the lower end of said outer mandrel, an outwardly projecting and upwardly facing portion formed on the lower ends of said linger members engageable with the downwardly facing shoulder of the landing nipple, packing means on said outer mandrel for sealing the space between said outer mandrel and the landing nipple, an inner mandrel dis` posed within the outer mandrel for limited longitudinal sliding movement between first and second positions relative to said outer mandrel, an outward projection Iformed on the lower end of said inner mandrel engageable with the lower ends of said second linger members to hold the latter outwardly from the axis of said outer mandrel when said inner mandrel is in its rst position, said inner mandrel projection being disengaged from said second linger members when said inner mandrel is in its second position to allow said second linger members to move inwardly towards said axis, and seal means between said inner and outer members to prevent liuid flow therebetween.

Other objects and advantages will become apparent in the course of the following detailed description.

In the drawings, forming a part of this application, and in which like parts are designated by like reference numerals throughout the same,

FIG. l is a schematic illustration of permanently installed well equipment.

FIGS. 2, 3 and 4 are schematic illustrations of various combinations of wire line handled equipment which may be run into the permanenti f installed well equipment of FIG. 1 to provide differing production and reworking tiow paths.

FIG. 5 is a sectional view `of a plugging tool embodying the principles of the present invention and usable in the combination illustrated in FIGS. 2 and 3 and shown installed in a dual bore packer.

FIG. 6 is a sectional View of a wire line running tool for landing and locking the plugging tool of FIG. 5 in the bore of a packer.

FIG. 7 is a sectional view of a wire line pulling tool for removing the plugging tool from a packer.

FIG. 8 is a sectional view of the plugging tool of FIG. 5 as modified for use as a wire line operated, latching device for well tools.

Referring now to the drawings, the permanent installation of FIG. l comprises a well casing 10` extending from ground level down through upper and lower producing formations, or zones, 11 and 12. The well casing is perforated at 13 and 14 at the level of these formations. Two tubing strings -15 and `15a extend downwardly through the casing and are packed off to the casing at the lower end by a conventional dual bore packer 16 at a level above the upper production Zone 11. Another conventional dual bore packer 17, modified in a manner to be hereinafter described, is set in the casing at a level between the upper and lower production zones 11 and 12.

Each tubing string 15 and 15a is provided with a landing nipple, 18 and 18a, respectively, at a level above the lower ends of the tubing strings, and a remotely controllable side port nipple 19 is connected into tubing string 15 between the landing nipple 1S and packer 16.

FIG. 2 illustrates a production combination wherein an extension hanger 21 is landed in landing nipple 13 to support extension pipe 22 having a safety joint 23 connected at its lower end which is landed in one bore of packer 17. The other bore of packer 17 is plugged by a plugging tool 24. In this combination, the side port nipple 19 is closed, and the upper zone 11 is produced through tubing string 15a while the lower Zone 12 is produced through the extension pipe 22 and the tubing string 15.

FIG. 3 illustrates a reworking combination wherein the side port nipple 19 has been opened to allow the lower zone 12 to again be produced through extension pipe 22 and tubing string 15, while the upper Zone 11 may be reworked through a flow path down through tubing string 15a to between packers 16 and 17 and upwardly through tne side port nipple 19 into the tubing-casing annulus.

FIG. 4 illustrates another reworking combination wherein the plugging tool 24 has been removed from the lower packer 17, and an extension hanger 21a has been landed in landing nipple 18a. An extension pipe 22a extends downwardly from the extension hanger 21a and is connected by safety joint 23a to packer 17. This combination allows the upper zone 11 to be produced through the side port nipple 19 and the tubing-casing annulus while reworking operations in the lower zone 12 may be carried out through tubing strings 15 and 15a and extension pipes 22 and 22a.

The plugging tool 24, illustrated in detail in FIG. 5, comprises a generally cylindrical inner mandrel 201 having an imperforate end plug, or sub 202 secured at the lower end thereof and sealed thereto. rIhe inner mandrel has an aperture 203 therethrough at its upper end for connection with a running tool to be hereinafter described. A split ring 204 encircles the main mandrel and projects outwardly therefrom. The lower end of end sub 202 has a downwardly and inwardly inclined seating surface 205.

Surrounding the inner main mandrel 201 and longitudinally slidable thereon is an outer mandrel unit comprising, from top to bottom, a lock mandrel 206, a packing mandrel 207 and a locater collet 2118, interconnected as shown.

The lock mandrel is undercut at 209 to form a fishing shoulder to enable the plugging tool to be engaged by a conventional fishing tool so as to be removed from a landed and locked position. A port 210 and exterior annular groove 211 are formed on the lock mandrel for attachment to a running tool to be hereinafter described.

A locking collet 212 surrounds the lock mandrel in longitudinally slidable relation thereto, with such movement being limited in an upward direction by the engagement of the collet 212 with an external fiange 213 formed on the lock mandrel. When the collet 212 is in its upper position illustrated, the lower ends 214 of collet finger members 215 engage the outwardly projecting lock mandrel shoulder 216 so that the outer surfaces 217 project outwardly from the nominal diameter of the plugging tool. When the collet 212 is moved downwardly on the lock mandrel, the collet finger ends 214 are free to move inwardly into lock mandrel groove 218 so that the outer surface 217 of the collet fingers may be flush with the exterior of the plugging tool. The collet fingers are provided with an outwardly projecting and downwardly facing seating surface 220.

The lock mandrel 206 has an interior annular groove 221 to allow longitudinal movement between the lock Vmandrel and the main mandrel, such movement being limited by the engagement of the split ring 204 with the ends ofthe annular groove 221. A packing assembly 222 surrounds the packing mandrel '207 and projects outwardly therefrom.

The locater collet 208 has a plurality of locater fingers 223 depending downwardly therefrom, said fingers each having a lower end 224 provided with an outer surface 226 which projects outwardly from the exterior of the plugging tool when the finger ends 224 engage the outwardly projecting inner mandrel surface portion 227. An outwardly projecting and upwardly facing seating surface 225 is provided on the lower ends of the fingers 223. The inner mandrel is shouldered at 22S to limit downward movement of the locater collet fingers 223 with respect thereto. When the locater collet 208 is moved upwardly relative to the inner mandrel 201, the lower finger ends 224 are free to move into the inner mandrel groove 229 so that the outer finger and surfaces 226 are flush with the exterior of the plugging tool. An O-ring 231 seals between the inner mandrel and the locater collet member 208.

An equalizing prong 235 fits loosely within the bore of the inner mandrel 201 and has the lower plug end thereof secured to the inner mandrel by shear pin 236 extending through inner mandrel port 237 into the prong. O-rings 2312 seal between the equalizing prong and the inner mandrel above and below the port 237. An axial passage 239 is formed in the lower end of the prong and communicates with a radial port 240 formed through the prong.

A running tool 250 illustrated in FIG. 6 is used to run the plugging tool into a bore of the packer 17 illustrated in FlG. 5. The running tool comprises three elements, a fishing neck 252, a core member 253 and a sleeve 254. The fishing neck is provided at its upper end with an undercut shoulder 256 and a threaded connection 257 for attachment to any suitable and conventional wire line tools (not shown).

The core member 253 is secured to the fishing neck and has an external flange 258 and a shear pin bore 259. Annular sleeve 254 surrounds the core member and can slide longitudinally relative thereto, with upward movement being limited by the engagement thereof with the fishing neck, and downward movement being limited by engagement with the core member flange 258. Shear pin ports '251 and 262 are provided in sleeve 254.

A pulling tool 275, illustrated in FIG. 7, is used to pull the plugging tool 24 from its landed and locked position in packer 17, and comprises a vertically disposed generally cylindrical mandrel 276 having a fishing neck 277 secured at the upper end thereof. The neck 277 is provided with a usual undercut shoulder 278 and a screw connection 279 for attachment to wire lines.

A core member 2.81 is slidably disposed for limited longitudinal movement within mandrel 276, and is pinned against relative movement thereto by shear pin 282. Shear pin retainer sleeve 283 surrounds mandrel 276 to hold shear pin 282 in place. The core member is biased upwardly within mandrel 276 by spring 284. A prong 255, fixed to or integral with the core member, extends downwardly therefrom, and is provided with a downwardly facing shoulder 286.

The mandrel 276 has a plurality of longitudinal slots 237 to receive elongated locking dog members 258 therein. Each locking dog is generally S-shaped in longitudinal cross-section, with the upper end 289 thereof extending upwardly from the upper end of the slot and between the mandrel and core member. The upper end of the dog member is in hooking engagement with sleeve portion 291 to limit downward movement thereof. The lower end of the locking dog is provided with an inwardly and upwardly extending hook 292. A dog spring 293 presses downwardly on thrust ring 294 to resiliently bias the dogs 288 downwardly to the position shown in FIG. 7. The lower ends of the dogs 288 `and the mandrel slots 287 are provided with complementary downwardly and inwardly inclined cam surfaces 295 and 2% which force lche dog hooks 292 inwardly as the dogs move downwardly. As will be seen in the drawing, the upper portion 297 of each dog is tapered away from core 231 so that only the inwardly projecting portion 298 of the dog member engages the core member, at a point below the upper end of slot 287, to allow rocking movement of the dog in a direction to move the dog hook 292 outwardly.

The core member has a downwardly sloping shoulder 299 disposed below the horizontal dog shoulder 300` for a purpose to be described.

The plugging tool 24 is installable in packer 17 in the following manner. The lock mandrel 206 of the plugging tool is inserted in sleeve 254 of the running tool so that the bottom of the sleeve will force the locking collet 212 downwardly until the lower ends of the collet fingers are iree to move inwardly into the reduced diameter locking mandrel groove 218. The lower ends of the collet ugers are restrained from outward movement by the engagement thereof in the recess 219 of the packing mandrel 207. A shear pin is inserted through port 262 in the running tool sleeve 254i to extend into the locking mandrel groove 211. At the same time, the external core lange 25S engages the upper end of the inner mandrel 201 and moves it downwardly with respect to the locking mandrel 206 so that the ports 259, 203, 210 and 261 of the inner mandrel, core, lock mandrel and sleeve will all be in registration. A second shear pin is then inserted in ports 259 and 203.

The running tool 250 is now lowered by wire line down to packer 17. Since the running tool sleeve 254 can slide downwardly on core 253, the collet fingers 223 will be positioned with respect to the inner mandrel 201 as shown in FIG. 5. When the plugging tool reaches the packer 17, the collet *linger portion 224 engages the packer shoulder 102 to prevent downward movement of the lock mandrel. The inner mandrel 201, however, moves downwardly until the collet fingers are free to move inwardly so that the whole plugging tool can be pushed downwardly through the bore 101 of the packer. The plugging tool is lowered until the lower ends 224 of the locating col-let iingers are below the packer shoulder 103.

The running tool is now raised, to raise the inner mandrel 201. The frictional engagement of the plugging tool packing element 222 with the packer bore 101 and the collet finger ends 224 with the packer wall resist upward movement of the outer mandrel, .allowing the inner mandrel to resume the position shown in FIG. 5, with the collet fingers 223 locked in their outer position so that they can not pass upwardly beyond the packer shoulder 103.

The running tool 250 is now jarred upwardly, causing both shear pins to fail, and the running tool is withdrawn from the well. Downward movement of the plugging tool 24 through the packer is prevented by the collet fingers 215. As the plugging tool moves downwardly,

the collet iinger ends 214 drag on the yupper wall 104 i of the packer so that the reduced diameter lock mandrel portion 216 locks the iingers in their outer position, shown in FIG. 5. In this position, the fingers engage the packer shoulder 102 to prevent further downward movement of the plugging tool.

To remove the plugging tool 24 from the packer 17, the pulling tool 275 is `attached to `a wire line -and run into the well until the pulling tool prong 235 abuts the equalizing prong 235 of the plugging tool. IThe pulling tool is now jarred downward to jar the equalizing prong 235, `causing the shear pin 236 to fail. The equalizing prong is then moved downwardly such a dist-ance that the portion of the shear pin remaining in inner mandrel port 237 is forced inwardly by the Huid pressure exteriorly thereof. The well uids can now flow through port 237 and upwardly between the inner mandrel and the equalizing prong, to equalize the pressures so as to facilitate removal of the plugging tool. Or, should the equalizing prong 235 be moved upwardly, the fluid may flow through port 237 and then upwardly through prong passage 239 and port 240 and then between the prong and inner mandrel to equalize the pressures. In either event, both of the O-rings 23S must be either above or below port 237 in order for the pressures to be equalized.

After pressure equalization, the running tool is again jarred downwardly. The prong shoulder 286 engages the upper end of the inner mandrel 201 of the plugging tool, forcing it downwardly so that the locating collet lingers 223 are free to move inwardly to allow upward removal of the plugging tool from the packer. At the same time, the upper end of the `lock mandrel 206 engages the lower ends of the pulling tool dogs 283, and forces them upwardly and outwardly so that the lock Imandrel 206 moves upwardly into the pulling tool mandrel 276. Alfter the locking mandrel 206 has moved sufciently far into the mandrel 276, the dogs 288 are free to be moved downwardly by spring 293, so that the dog hooks 292 move inwardly underneath the undercut shoulder 209 of the lock mandrel 206, to latch the running tool to the plugging tool.

The plugging tool may now be withdrawn from the packer by applying an upward pull to the pulling tool by wire line. Once at the surface of the well, the running tool 275 may be disengaged from the plugging tool lby applying pressure to the upper ends 239 of the dog members, which project through apertures 301, to pivot the dog member hooks 292 out from under the fishing shoulder of the plugging tool.

If the plugging tool is sanded, or otherwise locked, in the packer 17 so Ithat it cannot be removed, the pulling tool is again jarred downwardly to cause the shear pin 282 to fail. This releases the core member 281 for upward movement in mandrel 27e by spring 284. The core cam shoulder 299 cams against the dog shoulders 300, causing the dogs 280 to rock about the core cam shoulder 299 and the `upper end of slot 287 in a direction to move their hooks 292 outwardly from latched engagement with the undercut shoulder of the plugging tool lock mandrel. The pulling tool is now free to be withdrawn from the well.

FIG. 8 depicts another tform of the invention and illustrates the manner in which the plugging tool 24 has been modified to serve as a tool hanger 24a and in which essentially the same locking means is employed to lock the tool hanger in place in a bore of packer 17.

In this modification, the imperforate end. plug 202 has (been removed so that the tool hanger 24a can support a suitable well `tool T therebelow. The equalizing prong 23S has been replaced by ian annular ring valve V having an axial ow passage 239g therethrough to provide iluid communication down through the bore of the inner mandrel 201 to the interior of the well tool T.

The packing mandrel 207a has been modiied at its inner surface to extend the annular groove 221 in lock mandrel 206 downwardly, at 2210, in order to accommodate compression spring S therein. The upper end of spring S engages the flat lower surface of split ring 20M which is carried by the inner mandrel 201. As is apparent, spring S biases the inner main mandrel 201 upwardly relative to `the packing mandrel 207:1 and locater collet 208, to the position illustrated in FIG. 8, so that the lower ends 224i of the location iingers 223 are prevented from flexing inwardly towards the axis of the device by the outwardly projecting inner mandrel surface portion 227.

The tool hanger 24a is landed in packer 17 by the use of the running tool 250, illustrated in FIG. 6, in the same manner that the plugging tool 24 is landed; that is, the inner mandrel 201 is connected to the running tool core 253 by a shear pin extending through the registered ports 203 and 259, and the lock mandrel 206 is connected to the running tool sleeve 254 by a shear pin extending through sleeve port 262 into the lock mandrel groove 211. Since the running tool sleeve 25d is free to 9 drel projection being disengaged from said second finger members when said inner mandrel is in its second position to allow said second finger members to move inwardly towards said axis.

3. A well tool as set forth in claim 2 and further including means sealably closing the lower end of said inner mandrel and seal means between said inner and outer mandrels to prevent fluid flow therebetween.

4. A Well tool as set forth in claim 2 and further including spring means disposed between said inner and outer mandrels for biasing said inner mandrel to its first position relative to said outer mandrel.

5. A well tool adapted to be landed in a landing nipple having spaced apart upwardly and downwardly facing shoulders, comprising: a vertically disposed generally cylindrical outer mandrel, a collet mounted on the upper end of said outer mandrel for limited longitudinal movement therein between first and second positions, a first plurality of elongated resilient finger members each having one end mounted on said collet and extending longitudinally along said outer mandrel, an outwardly projecting downwardly facing portion formed on the free ends of said first finger members engageable with the upwardly facing shoulder of said landing nipple, said outer mandrel having an outward projection thereon engageable with said first finger members to hold said first finger member portions outwardly from the axis of said outer mandrel when said collet is in its first position, said outer mandrel having a groove therein to allow said first linger member portions to be moved inwardly towards said axis when said collet is moved towards its second position, means on said mandrel for retaining said finger members in their inward positions relative to said axis when said collet is in its second position, a second plurality of downwardly extending, resilient, elongated finger members secured at the upper ends thereof to the lower end of said outer mandrel, an outwardly projecting and upwardly facing portion formed on the lower ends of said second finger members engageable with the downwardly facing shoulder of the landing nipple, packing means on said outer mandrel for sealing the space between said outer mandrel and the landing nipple, an inner mandrel disposed within the outer mandrel, interengaging means on said inner and outer mandrels for permitting limited longitudinal sliding movement of said inner mandrel between first and second positions relative to said outer mandrel, an outward projection formed on the lower end of said inner mandrel engageable with the lower ends of said second finger members to hold the latter outwardly from the axis of said outer mandrel when said inner mandrel is in its first position, said inner mandrel projection being disengaged from said second finger members when said inner mandrel is in its second position to allow said second finger members to move inwardly towards said axis.

6. A latchable well tool adapted to be landed and latched in a landing nipple having spaced apart upwardly and downwardly facing shoulders, comprising: a vertically disposed generally cylindrical outer mandrel, a collet mounted on the upper end of said outer mandrel for limited longitudinal movement therein between first and secl0 ond positions, a first plurality of elongated resilient finger members each having one end mounted on said collet and extending longitudinally along said outer mandrel, an outwardly projecting and downwardly facing portion formed on the free ends of said first finger members engageable with the upwardly facing shoulder of said landing nipple, said outer mandrel having an outward projection thereon engageable with said first finger members to hold said first finger member portions outwardly from the axis of said outer mandrel when said collet is in its first position, said outer mandrel having `a groove therein to allow said first finger member portions to be moved inwardly towards said axis when said collet: is moved towards its second position, a second plurality of downwardly extending, resilient, elongated finger members sccured at the upper ends thereof to the lower end of said outer mandrel, an outwardly projecting and upwardly facing portion formed on the lower ends of said second finger members engageable with the downwardly facing shoulder of the landing nipple, packing means on said outer mandrel for sealing the space between said outer mandrel and the landing nipple, an inner mandrel disposed within the outer mandrel, interengaging means on said inner and outer mandrels for permitting limited longitudinal sliding movement of saidinner mandrel between first and second positions relative to said outer mandrel, an outward projection formed on the lower end of said inner mandrel engageable with the lower ends of said second finger members to hold the latter outwardly from the axis of said outer mandrel when said inner mandrel is in its first position, said inner mandrel projection being disengaged from said second finger members when said inner mandrel is in its second position to allow said second finger members to move inwardly towards said axis, first seal means between said inner and outer mandrels to prevent fluid flow therebetween, a radial passage through said inner mandrel below said first seal means, a plug member disposed in said inner mandrel for longitudinal sliding movement therein, a shear pin extending through said radial passage into said plug member to normally hold said plug member adjacent said radial passage, second seal means disposed between said plug member and said inner mandrel to prevent iiuid flow through said radial passage, and a passage extending through said plug member from the lower to the upper ends thereof.

7. A well tool as set forth in claim 6 and further including means sealably closing the lower end of said inner mandrel.

8. A well tool as set forth in claim 6 and further including spring means disposed between said inner and outer mandrels for biasing said inner mandrel to its first position relative to said second mandrel.

References Cited in the file of this patent UNITED STATES PATENTS 2,394,977 Boynton Feb. 19, 1946 2,885,006 Long et al. May 5, 1959 2,901,045 Schramm Aug. 25, 1959 2,944,605 Dollison July 12, 1960 2,962,097 Dollison Nov. 29, 1960 

